1. Field of the Invention
The present invention generally relates to a display system for a compact electronic appliance. More specifically, the present invention is directed to an information display system used for such compact electronic appliances equipped with display units having different display sizes and capable of properly displaying display information which is received from the same display information source.
2. Related Art of the Invention
In general, conventional compact electronic appliances for displaying characters employ dot matrix type liquid crystal display apparatuses as display units. The data to be displayed, for instance character code, are converted into image data or bit patterns, and the converted display data are stored in the screen memory corresponding to the dots constituting the liquid crystal display panel, and thereafter the display operation is performed in accordance with the contents of this screen memory.
On the other hand, since many consumers have expressed a need for more easily observable display screens, the sizes of the present display screens are being enlarged without changing the basic functions of the display system. In such a case, although there is no modification in the calculation control and memory control, either control unit or LSI employed in the electronic appliance must be discretely prepared so as to be fitted to the modification of the display apparatus. Therefore, there exists such an economical problem that the design of LSI employed in the display apparatus must be modified in order to accept such a slight change in the display screen size.
Furthermore, very recently an information processing apparatus has been marketed that can execute a program previously stored in an external storage medium, for instance, an IC card, while connecting the IC card to this information processing apparatus.
In accordance with such an information processing apparatus, when the program stored in the IC card is executed, e.g. information display program is executed, the display data is received from the IC card together with the information on the line number and column number for the display purpose, and the display data is merely displayed on the designated position of the display unit.
However, there are various information processing apparatuses in the same series but of different size. As a consequence, when, for instance, such a program to display data of a 3-line.times.5-column display unit has been stored in an IC card, the overall screen of this display unit can be effectively utilized so as to display this display data only under the condition that the screen size of the display unit is 3 lines.times.5 columns. To the contrary, when other differently sized display units, for example, a screen size of 4 lines.times.10 columns are employed instead of the above-described screen size of 3 lines.times.5 columns, and the above-described IC card is utilized, the display data is displayed only within a display area of 3 lines.times.5 columns. This may cause insufficient display of the effective display range of the display unit, and also worse display appearances of the display data.